FLCC Inductively Coupled Plasma Simulations Using...
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Workshop November 19, 2003 1 3 2 4 6 5 7 9 8 10 12 11 Acknowledgment Funded by Advanced Micro Devices, Applied Materials, Atmel, Cadence, Canon, Cymer, DuPont, Ebara, Intel, KLA-TENCOR, Mentor Graphics, Nikon Research, Novellus Systems, Panoramic Techhnologies, Synopsis, Tokyo Electron, and the UC Discovery Grant. Additional funding by ERL FLCC Inductively Coupled Plasma Simulations Using FEMLAB Mark A. Nierode , Prof. David B. Graves, University of California, Berkeley Computational Domain Motivation Modeling Approach The Problem 2003 Main Objectives Reproducing C 4 F 8 Experiments? Electron Energy Plasma Density Future Goals Immediate Goals Funded by Milestones: Plasma Technology Preliminary simulator development 1 (Milestone 4) …Develop 2-D, non-isothermal, compressible flow simulator for dual frequency capacitive discharge and for Centura… •Preliminary simulator development 2 (Milestone 5) Develop global discharge model for multiple rare gas mixtures…and have preliminary comparisons with available experimental trends in the Centura on etch rates... -Etch by-product formation in plasmas is often important -Etch by-products form an intrinsic part of the plasma chemistry -Etch rate, uniformity, and critical dimension (CD) control are all affected -Little is known about etch by-products -Few measurements -Essentially no modeling ⇒Develop combined modeling-experimental program to study etch by-products −Develop neutral transport and plasma model −Coordinate with experimental studies (Jerry Hsu - UCB) −Study mechanisms by which PFCs decompose and reform −Study novel materials: metal gate, high k and low k candidates • Investigate Ar/C 4 F 8 plasma chemistry – Plasma chemistry (how does C 4 F 8 decompose, reform?) – Surface reactions (chamber wall depostion, re-etching, wafer re-deposition) – Optimize effluent composition (CF 4 ?) • Investigate novel materials? – RuO x ? – Low k •Etch products form in plasma & CD effects observed –Example: Silicon etching with Cl 2 •Neutral transport and redeposition plays a key role in etch performance. •Redeposition of silicon from gas phase on wafer can lead to loss of CD control. •In some cases, environmental hazards result from by-product formation • Study the transport of etch byproducts for novel materials – metal gate, high k, and low k applications • Study transient wall deposition and the effect on the plasma chemistry • Investigate possible migration of deposited species • Investigate pulsing flows Approximations reduce computational loads – Azimuthal symmetry – Continuum approximation – Neglect capacitive coupling… •Modeling platform is FEMLAB, a commercial finite element program •Model includes reactor scale plasma and neutral components •Propose and implement chemistry/mechanism of interest •Combine reactor model with experimental reactor diagnostics (Jerry Hsu - UCB) • 150 W power dictated by Hsu experiments • Electron temperature agrees with L&L global model 20 sccm Ar P=10 mtorr • 20 sccm Ar, p=10 mtorr, P = 150 W • Argon number density follows temperature profile • Minimal pressure gradients • Implement chemistry for Ar/C 4 F 8 chemistry • Investigate mechanism by which PFCs decompose and reform • Investigate the role of chamber surface reactions on etching • Compare with experiments • Etching, deposition, re-etching Neutral Argon Results Milestones: Plasma Technology Surface model refinement (Milestone 2119) Perform global simulations with multiple rare gases to determine neutral/ion flux ratios at surfaces… Make adjustments to the profile simulations using the feedback from the experiments, MD simulations and reactor scale simulations. The Problem (cont) Mask Redeposited sidewall film CD 0 Mask Silicon CD f Vahedi et.al., 1999 Dry Process Symposium, Tokyo Ar (*0.1) C4F8 CF4 CF3 CF2 CF F NormalFlowRate DoubleFlowRate 0 0.5 1 1.5 2 2.5 3 Density (10 13 cm -3 ) Neutral Species Electron Density Profile Comparison 0.0E+00 1.0E+17 2.0E+17 3.0E+17 4.0E+17 5.0E+17 0 5 10 Radius [cm] Number Density [#/m3] FEMLAB P=150 W, p=10 mtorr Exp. Data Adjusted P=?, p=10 mtorr Electron density profile agrees reasonably well with Langmuir probe scan in experimental chamber Figure: Dominant neutral species density measured by using Hiden. Note that Ar neutral density was multiplied by a factor of 0.1. • How important are the surface reactions? • Can we reproduce experimental results? • Can we describe the reformation of PFCs? • Will the simulation translate to other tools? Experimental Data from Jerry Hsu
Transcript of FLCC Inductively Coupled Plasma Simulations Using...
WorkshopNovember 19, 2003
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10 1211
AcknowledgmentFunded by Advanced Micro Devices, Applied Materials, Atmel, Cadence, Canon, Cymer, DuPont, Ebara, Intel, KLA-TENCOR, Mentor Graphics, Nikon Research, Novellus Systems, Panoramic Techhnologies, Synopsis, Tokyo Electron, and the UC Discovery Grant.
Additional funding by ERL
FLCCInductively Coupled Plasma Simulations Using FEMLAB
Mark A. Nierode, Prof. David B. Graves, University of California, Berkeley
Computational Domain
Motivation
Modeling Approach
The Problem2003 Main Objectives
Reproducing C4F8 Experiments?
Electron EnergyPlasma Density
Future GoalsImmediate Goals
Funded by
Milestones: Plasma TechnologyPreliminary simulator development 1 (Milestone 4)
…Develop 2-D, non-isothermal, compressible flow simulator for dual frequency capacitive discharge and for Centura…
•Preliminary simulator development 2 (Milestone 5)Develop global discharge model for multiple rare gas mixtures…and have preliminary comparisons with available experimental trends in the Centura on etch rates...
-Etch by-product formation in plasmas is often important-Etch by-products form an intrinsic part of the plasma chemistry-Etch rate, uniformity, and critical dimension (CD) control are all affected
-Little is known about etch by-products-Few measurements-Essentially no modeling
⇒Develop combined modeling-experimental program to study etch by-products−Develop neutral transport and plasma model−Coordinate with experimental studies (Jerry Hsu - UCB)−Study mechanisms by which PFCs decompose and reform−Study novel materials: metal gate, high k and low k candidates
• Investigate Ar/C4F8 plasma chemistry– Plasma chemistry (how does C4F8 decompose, reform?)– Surface reactions (chamber wall depostion, re-etching,
wafer re-deposition)– Optimize effluent composition (CF4?)
• Investigate novel materials?– RuOx?– Low k
•Etch products form in plasma & CD effects observed–Example: Silicon etching with Cl2
•Neutral transport and redeposition plays a key role in etch performance.
•Redeposition of silicon from gas phase on wafer can lead to loss of CD control.
•In some cases, environmental hazards result from by-product formation
• Study the transport of etch byproducts for novel materials
– metal gate, high k, and low k applications
• Study transient wall deposition and the effect on the plasma chemistry
• Investigate possible migration of deposited species
• Investigate pulsing flows
Approximations reduce computational loads– Azimuthal symmetry – Continuum approximation– Neglect capacitive coupling…
•Modeling platform is FEMLAB, a commercial finite element program
•Model includes reactor scale plasma and neutral components
•Propose and implement chemistry/mechanism of interest
•Combine reactor model with experimental reactor diagnostics (Jerry Hsu - UCB)
• 150 W power dictated by Hsu experiments• Electron temperature agrees with L&L global model
20 sccm ArP=10 mtorr
• 20 sccm Ar, p=10 mtorr, P = 150 W• Argon number density follows temperature profile• Minimal pressure gradients
• Implement chemistry for Ar/C4F8 chemistry
• Investigate mechanism by which PFCs decompose and reform
• Investigate the role of chamber surface reactions on etching
• Compare with experiments• Etching, deposition, re-etching
Neutral Argon Results
Milestones: Plasma TechnologySurface model refinement (Milestone 2119)
Perform global simulations with multiple rare gases to determine neutral/ion flux ratios at surfaces… Make adjustments to the profile simulations using the feedback from the experiments, MD simulations and reactor scale simulations.
The Problem (cont)
Mask
Redepositedsidewall film
CD0
Mask
SiliconCDfVahedi et.al., 1999 Dry Process Symposium, Tokyo
Ar(*0.1)
C4F8CF4CF3CF2CFF
Nor
mal
Flow
Rat
e
Dou
bleF
low
Rat
e
0
0.5
1
1.5
2
2.5
3
Density (1013 cm-3)
Neutral Species
Electron Density Profile Comparison
0.0E+00
1.0E+17
2.0E+17
3.0E+17
4.0E+17
5.0E+17
0 5 10Radius [cm]
Num
ber D
ensi
ty [#
/m3]
FEMLAB P=150 W,p=10 mtorr
Exp. Data AdjustedP=?, p=10 mtorr
Electron density profile agrees reasonably well with Langmuir probe scan in experimental chamber
Figure: Dominant neutral species density measured by using Hiden. Note that Ar neutral density was multiplied by a factor of 0.1.
• How important are the surface reactions?
• Can we reproduce experimental results?
• Can we describe the reformation of PFCs?
• Will the simulation translate to other tools?
Experimental Data from Jerry Hsu
